Drill for oil and gas wells



Nov. 3, 1931. 5, w, s o 1,830,625

DRILL FOR OIL AND GAS WELLS Filed Feb. 16, 1927 ATTORNEY Patented Nova?1931 (moms w. scnaocx, or mnoao,.1nmo

mm. ton on. mass wELLs Application filed Iebr'uary .18, 1927. Serial No.168,752.

This invention relates to drills and more particularly to cable rockdrills used in bormgoil and gas wells.

i A primary object of the invention is to provide a drill of thischaracter having a one ,piece head provided with aplurality of bits orcutters of different types so arranged as to effectively cut across eachothers path through the rock and so produce a round hole 10 withoutnecessitating the use of other tools,

and which'cutters are adapted to be changed fre uently to provide fordrilling a hole of uniiorm' size throughout. 7 Another'object' is to somount the hits or 16 cutters in the head-that they may be readily.removed by the operator for sharpening or replacing when dulled, thussaving expense vention,

Fig. 2 is a similar view taken in a plane at 80 right angles to Fig.1,

. ig. 3 is a transverse vertical section through the head of the drillwith the shank broken off for convenience in, illustration,

Fig. 4 is a bottom plan view of the tool with the bits in place, and

Fig. 5 is a similar view of the head with the bits removed.

In the embodiment illustrated a solid substantially cone-shaped head 1is shown which merges at its apex into a shank or stem 2 provided at itsupper end with a reduced threaded terminal 3 for'connection with thedrilling apparatus. A plumb or guide r' 4 is mounted on the upper end ofthe shan 2 being seated on a shoulder 40 formed at the inner end of areduced portion 2a ofthe shank. This plumb ring is secured in tion by aset screw' 5 passin radially em ,n through and engaging the eachprovided with an angular portion 17 to with a plurality oflongitudinally extending peripherally spaced sand grooves 6 betweenwhich in the head are formed sockets 8 arranged obliquely as shown inFig. 3 to receive the threaded shanks 14 of the cutters or bits, four ofwhich are here shown and which have said shanks extended-in longitudinalalinement with the bodies of the cutters. A central s0cket7 is larger insize than those and is designed to receive a master cutter 9 which ismade in the form of a bull bit, with a reduced threaded rear end forinsertion in the socket 7. The sockets 8 are inclined upwardly andinwardly as shown in Fig. 3 so that the bits 10, 11, 12 and 13 which aremounted therein are inclined outwardly at their cutting edges to providea clearance for the four cutterswhile drilling. This arrangement of thebits 8 and their sockets adapts the cutting strain to beborne by thehead 1 and not at the 70 'junctionz giif the bits with the head such aswould-be' liable to shear off the bits at this point, These cutters arearranged in pairs, those of each pair being diametrically oppo site eachother two of said'cutters being 0111881 cutters and two bull bits. Thecutters or bits are held in their sockets by set screws 16 as shownclearly. in Fig. 3 and are preferably receive a wrench for screwing theminto and out of the sockets. The two chisel bits 10 and '11 are setopposite each other with cutter edges on two sides of the head and thetwo bull bits 12 and 13 are set with their cutting corner edges from thecenter to the outer edge of the drill base on two sides as is shownclearly in Figs. 1 and 4 while the master drill, bit 9 is set with thecutting corner edges to the center of the two chisel bits so that all ofthe rock. will be cut out since these bits cut across each others pathsthereby insuring the formation of a round hole without necessitating theuse of any other tools.

The master bit 9 has mounted in the riphery' thereof four screwsarranged at 'ametrically zgiposite points so' that the heads 18 thereof1 thespa'c'es between the master bit and the other bits and said headsare made I K I concave on their outer faces to fit the shanks The outerface of the head 1 is provided of -the cutting. bits as shown at 19 inFig. i-

2 l f I 1,880,095

These screws 18 which are threaded into the master bit 9 operate to holdthebits 10 '11, 12 and 13 rigidly in cutting osition and t us insure theo eration of the its in unison.

5 From e above description, it will be obvious that this drill has itshead and shankconstructed from a single piece whereby strength anddurability are, provided and the conesha ed or beveled construction ofthe head m wi the bit receiving sockets arranged at an incline provide aclearance for the bits while mg. Without further description, it isthought that thefeatures and advantages of the in-,- 15 vention will bereadily apparent to those skilledin the art, and itwill, of course, beunderstood that changes in the form, proportion and minor details ofconstruction may be resorted to, without departing from the 30 spirit ofthe invention or its scope as claimed.

I claim A multi-bit drill comprising a substantially cone-shaped headhaving a shank extending from the apex thereof, sand grooves arranged 18in the outside walls of said head, a central socket opening through thebase of the head and surroundedby a plurality of concentrically arran dsockets, the central socket being lar er t an the others, a masterdrill'bit a6 inserte in said central socket and pairs of chisel and bullbits mounted in the other sockets, these bits being arranged inpairsdiametrically opposite each other, and locking elements arranged betweensaid master 35 bit and the ad'acent bits.

. iirEORGE W. SCHROCK.

